So I finally figured it out...
The difference is quite noticeable.
Streaming 192KHZ from Musicbee, my audiophile NAS (network streaming server) to BubbleUPNP via the two Subsonic and BubbleUPNP plugins was a bit convoluted as there's barely any steamlined instruction, tutorial but it was definitely worth it.
My problem with MusicCast was I felt left wanting more. The Musiccast was an improvement over my first up which were small 12 inch bluetooth studio monitors and a valve amp (Presonus 3.5s and a Dared SL-2000A, recommended for beginners looking for work but swap the Dared with another preamp of choice) but in a way despite tweaking the settings to be as bandwidth intensive as possible, it felt slightly like a Bluetooth Deluxe...
Because it lacked that fullness.
Streaming from BubbleUPNP guarantees finer sparkle with its ability to stream guaranteed 24bit, but its streaming from MusicBee that gives it that punchy fullness to the instruments that streaming standalone from the SONOS / Yamaha MusicCast lacks, along with finer details in the hi hat, cymbal, percussive slides and noticeable nuance to sound.
Plus Equaliser support! How about that.
By the way, a TUTORIAL below:
"My MusicBee Can't Stream, Not Working!" :
If suddenly the stream stops working and you get the error "(Your streamer) is not ready to output", don't fret-- I've tested restarting Musicbee and BubbleUPNP, restarting the PC, deleting Subsonic (thinking I didn't need it), changing BubbleUPNP's settings (like thinking I needed to input BubbleUPNP's "Internet Access), touching the settings thinking I needed to compromise quality for bandwidth (don't! Especially if you have NBN!), even changing the IP and Port used to connect MusicBee to my streamer. None of these work!
What Does work is
1. Deleting both the Upnp and Subsonic dlls for MusicBee and
2. copying both original dlls straight off the rar files.
That's it! And then you just log back in to the Subsonic plugin with your given Port number and details.
This isn't a bid to do away with amps completely because the overall sound from the WXA-50 MusicCast is already quite good, but it does help with feeling you aren't getting the most out of your buck because by streaming straight to your computer outside of the given MusicCast app, and succeding in this, you already pretty much have!
My Khadas Tone Board Pro is going to take this sound to the next level, sounding quite close to a $1500+ DAC amp for less than $150AUD (for real!) and having done all I can to welcome it home, my ears can't wait.
PS: Get the MusicBee Remote App for Android and iOS and you've got yourself a cozy worry-free set-up!
Apparently all you have to do is plug in your phone by USB to your PC, MusicBee detects it, and once detected, try the Remote App and success!
Anyway, just sharing this info because this took me a whole night's worth of sleep but I'm really pleased with the results. It sounds amazing. I'm really happy with this. And all this for under a $1000.
Lastly, instructions written by captain_paranoia at the MusicBee forum*:
And to install Subsonic
2. log into the given link at the starting page
3. create your account
4. get the music folder ready, get the directory link correct
5. give your account permission for all files
*CCA refers to your media renderer / streamer
**NAS refers to the computer / server storing the files
(I also use ListFix-- a Java app-- to convert all my phone's playlists to the PC easily. And be sure to convert the M3U not M3U8 so MusicBee detects your playlists. You're welcome!)